This worked for a little bit. I've placed the antennas roughly 50cm apart and increased the baud rate to 115200 as @Whandall suggested. Here's what my receiver serial monitor showed:
SPI Speedz = 10 Mhz
STATUS = 0x0e RX_DR=0 TX_DS=0 MAX_RT=0 RX_P_NO=7 TX_FULL=0
RX_ADDR_P0-1 = 0x3130303030 0xc2c2c2c2c2
RX_ADDR_P2-5 = 0xc3 0xc4 0xc5 0xc6
TX_ADDR = 0xe7e7e7e7e7
RX_PW_P0-6 = 0x20 0x20 0x20 0x20 0x20 0x20
EN_AA = 0x3f
EN_RXADDR = 0x03
RF_CH = 0x4c
RF_SETUP = 0x01
CONFIG = 0x0f
DYNPD/FEATURE = 0x00 0x00
Data Rate = 1 MBPS
Model = nRF24L01+
CRC Length = 16 bits
PA Power = PA_MIN
ARC = 0
Hello World
Hello World
I'll try moving them further apart to see if they work, although they didn't the last time I did it.